The present invention relates to a control circuit for automobiles, and particularly to a control circuit in cooperation with a personal radio paging unit to achieve a multi-functional control to automobiles.
In recent years, remote controllers have been widely used in anti-theft apparatus for automobiles. However, as the power of the remote controllers is limited, the remote controller can only be properly operated within a short distance range. Thus, once a thief has stolen a car and left the location where the car was parked, the provision of the remote controller and a corresponding circuit related thereto will be in vain.
Therefore, an anti-theft system for automobiles employing a personal radio paging unit has been developed. In the present system, an anti-theft circuit is installed within the car directly in electrical connection with a ring output of the personal radio paging unit. Once the car owner discovers the car has been stolen, the car owner may control the car by way of dialing a telephone. The personal radio paging unit within the car will receive a radio signal generated based on a signal transmitted from the calling telephone and generate an activating signal to turn on the anti-theft circuit thereby cutting off the power and the ignition coil circuits of the car and turning on an alarm within the car. However, such a system merely uses a ringing signal from the personal radio paging unit to disable/enable the circuits within the car and perform an anti-theft function without controlling other parts of the car such as door lock knobs. Thus, the car owner has to additionally carry a remote controller to control the remaining part of the car.